In semiconductor technology, electronic devices are formed on semiconductor wafers in a sequence of process steps under clean-room conditions. To handle and store the wafers, auxiliary objects are necessary. To achieve a good yield in the fabrication of electronic devices and a good quality of the electronic devices, steps must be taken to ensure that no dust particles can reach the wafer surface. This requires that the auxiliary objects for handling and storing the wafers, which come into direct contact with the wafers, should also be free of dust particles, for dust particles on the auxiliary objects may be transferred by such contact to the wafers. A typical example of an auxiliary object for handling semiconductor wafers are the so-called carriers, which are formed from quartz glass for particular applications. Such carriers consist, for example, of four long, interconnected quartz rods which are provided with slits and are so arranged that several wafers can be received by one quartz carrier, the wafers standing in the slits in a fixed position. In such quartz carriers, the wafers are transported to a further apparatus, such as a furnace, for carrying out a given process step. Dust particles are transferred by the contact between the wafer and the carrier and between the carrier and further transport means. As a result, the auxiliary objects, i.e., the quartz carriers, must be cleaned to minimize dust particle transfer.
It is common practice to blow the auxiliary objects clean with a nitrogen gun. This process, however, has the disadvantage that the dust particles are blown into the surrounding space, where they can settle on and contaminate other auxiliary objects or wafers. In addition, the reliability of this process depends on the operator, so that the cleaning process is not easily reproducible. It is also common practice to subject auxiliary objects, particularly quartz objects, to a wet cleaning process. However, such a process is very time-consuming. Moreover, wet cleaning roughens the surfaces of quartz parts, so that recontamination by dust particles is easily possible. Consequently, an improved cleaning apparatus which overcomes the aforementioned problems while still providing a high degree of dust particle removal is greatly desired.